Submission #850949

#	Time	Username	Problem	Language	Result	Execution time	Memory
850949		wakandaaa	Chessboard (IZhO18_chessboard)	C++17	70 / 100	159 ms	8400 KiB

chessboard

#include <bits/stdc++.h>
#define int long long

using namespace std;

#define file ""

#define mp make_pair
#define fi first
#define se second
#define all(x) x.begin(), x.end()

#define getbit(x, i) (((x) >> (i)) & 1)
#define bit(x) (1LL << (x))
#define popcount __builtin_popcountll

mt19937_64 rd(chrono::steady_clock::now().time_since_epoch().count());
int rand(int l, int r) {
    return l + rd() % (r - l + 1);
}

const int N = 1e6 + 5;
const int mod = (int)1e9 + 7; // 998244353;
const int lg = 25; // lg + 1
const int oo = 1e9;
const long long ooo = 1e18;

template<class X, class Y> bool mini(X &a, Y b) {
    return a > b ? (a = b, true) : false;
}
template<class X, class Y> bool maxi(X &a, Y b) {
    return a < b ? (a = b, true) : false;
}
void add(int &a, int b) {
    a += b;
    if (a >= mod) a -= mod;
    if (a < 0) a += mod;
}

struct rec {
	int x, y, u, v;
	rec (int _x = 0, int _y = 0, int _u = 0, int _v = 0) {
		x = _x;
		y = _y;
		u = _u;
		v = _v;
	}
};
int n, k;
vector<rec> subrec;
int area = 0;
int res = ooo;

signed main() {
    ios::sync_with_stdio(false);
    cin.tie(0);

    // freopen(file".inp", "r", stdin);
    // freopen(file".out", "w", stdout);

    cin >> n >> k;
    for (int i = 1; i <= k; ++i) {
        int x, y, u, v;
        cin >> x >> y >> u >> v;
        --x, --y, --u, --v;
        subrec.push_back(rec(x, y, u, v));
        area += (u - x + 1) * (v - y + 1);
    }
    for (int i = 1; i < n; ++i) if (n % i == 0) {
        int d = n / i;
        int a = (d * d + 1) / 2 * i * i;
        int b = (d * d) / 2 * i * i;
        int cnt = 0;
        for (auto [x, y, u, v] : subrec) {
            if ((x / i) % 2 == (y / i) % 2) ++cnt;
        }     
        res = min(res, (a - cnt) + (area - cnt));
        res = min(res, (b - (area - cnt)) + cnt);
    }

    cout << res;

    return 0;
}

/*

*/

• Subtask 1: 8 / 8
• Subtask 2: 8 / 8
• Subtask 3: 15 / 15
• Subtask 4: 16 / 16
• Subtask 5: 23 / 23
• Subtask 6: 0 / 30